Multiple sclerosis means a definite diagnosis of at least one of the following:
- two or more separate clinical attacks, confirmed by magnetic resonance imaging (MRI) of the nervous system, showing multiple lesions of demyelination
- well-defined neurological abnormalities lasting more than 6 months, confirmed by MRI imaging of the nervous system, showing multiple lesions of demyelination; or
- a single attack, confirmed by repeated MRI imaging of the nervous system, which shows multiple lesions of demyelination which have developed at intervals at least one month apart.
The diagnosis of multiple sclerosis must be made by a specialist.